Consistency is one of the cornerstones of good usability. Although it is possible in advanced CMSs to create radically different page layouts according to content type, it's important that areas outside of the page’s content area remain consistent across the site for wayfinding purposes. This can be controlled through carefully designing and implementing page templates.... Read more about ✎ Technique: Consistent layout
In long lists of links, it's helpful to show users which links they've already followed so they can focus on unseen content. Browsers do not tend to let you style visited links with anything but the color property.
✓ Good example
With link styling, as with many aspects of web-interface design, you can aid comprehension by capitalizing on convention. By default, browsers style unvisited...
People use different methods to find web content. Screen-reader users might prefer navigation regions, people with dyslexia might prefer the logic of a site map, and people with motor impairments might prefer to type in a search term using a search facility.
It's important to provide consistent navigation regions to navigate between a site's pages and—where there is a lot content on each page—between sections of pages.
Clear, logical and consistent navigation tools reliably help people find their way to the content they need and recover quickly when they are in the wrong place. This helps everyone but particularly people with visual, cognitive, or motor impairments who might otherwise find it time-consuming to locate the information they need....
When positioning elements using CSS, it's possible to place them in a position that does not reflect their location in the source order. This can have unexpected side effects for keyboard-navigation users.